This invention relates to a keyboard musical instrument and, more particularly, to dampers appropriate to a keyboard musical instrument and a keyboard musical instrument equipped with the dampers for damping vibrations of strings.
A damper is an essential component of an acoustic piano. The damper is linked with a key. The key gives rise to reciprocal motion of a damper head assembly. While the key is resting, the damper head assembly is held in contact with a set of strings, and prevents the set of strings from resonation with vibrating strings. A pianist is assumed to depress the key for generating a piano tone. The depressed key gives rise to upward motion of the damper head assembly, and, accordingly, the damper head assembly is spaced from the associated set of strings. The set of strings gets ready for vibrations. A hammer strikes the set of strings, and the set of strings vibrates for generating the piano tone. When the pianist releases the depressed key, the key is moved toward the rest position, and permits the damper head assembly to be brought into contact with the vibrating strings. The vibrations are taken up with the damper head assembly, and the piano tone is decayed. Thus, the damper deeply concerns the length of the piano tone.
FIG. 1 shows a typical example of the damper incorporated in a standard grand piano. In FIG. 1, the right side is closer to a pianist sitting in front of the standard grand piano than the left side, and is hereinbelow referred to as xe2x80x9cfrontxe2x80x9d. Oppositely, the left side is referred to as xe2x80x9crearxe2x80x9d.
The prior art damper is designated in its entirety by reference numeral 1. The prior art damper 1 is associated with a key 2 and a set of strings 3. Although an action mechanism 2a and a hammer assembly 3a are provided for the key 2, the action mechanism 2a and the hammer assembly 3a are similar to those of the standard grand piano, and no further description is hereinbelow incorporated.
A note of the scale is assigned to the key 2, and the set of strings 3 generates a piano tone with the note identical with that assigned to the key 2. While the key 2 is resting, the prior art damper 1 is held in contact with the set of strings 3, and prohibits the set of strings 3 from vibrations. When a pianist generates the piano tone, he or she depresses the key 2, and the key 2 actuates the prior art damper 1. The prior art damper 1 leaves from the set of strings 3, and permits the set of strings 3 to vibrate for generating the piano tone. The depressed key 2 actuates the action mechanism 2a, and the jack of the action mechanism 2a escapes from the hammer assembly 3a. The escape gives rise to free rotation of the hammer assembly 3a, and the set of strings 3 is struck by the hammer assembly 3a. The set of strings 3 vibrates so as to generate the piano tone. Thus, the set of strings 3 is allowed to vibrate while the prior art damper 1 is being spaced therefrom. The position at which the prior art damper 1 prohibits the set of strings 3 from the vibrations is hereinbelow referred to as xe2x80x9crest positionxe2x80x9d, and the position at which the prior art damper 1 permits the set of strings 3 to vibrate is hereinbelow referred to as xe2x80x9ctone generating positionxe2x80x9d.
The prior art damper 1 comprises a damper lever flange 4, a damper block 5, a damper wire 6, a damper head assembly 7, which includes a damper head 7A and a pair of damper felts 8, and a damper flange 9. The damper lever 4 is swingably supported by the damper lever flange 9, and forwardly projects therefrom. The damper lever 4 is formed of wood, and holes are formed in the damper lever 4. The damper block S is connected to the damper lever 2 by means of a pin, and upwardly projects from the damper lever 2. The damper block 5 is rotatable around the pin. The damper wire 6 is fixed to the damper block 5, and upwardly projects therefrom. A guide rail 10 is located over the damper flange 9, and a hole is formed in the guide rail 10. The damper wire 6 passes through the hole, and projects over the guide rail 10. The hole is wide enough to permit the damper wire 6 smoothly to move therethrough. The damper head assembly 7 is fixed to the upper end of the damper wire 6.
As described hereinbefore, the damper head 7A and the pair of damper felts 8 as a whole constitute the damper head assembly 7. The damper head 7A is formed of wood, and the damper felts 8 are formed of felt. Hard wood is preferable for the damper head 7A. Isunoki or Onoore is large in specific weight, and the damper head 7A is usually formed of one of these kinds of hard wood. Isunoki or Onoore are Japanese names. Their botanical names are xe2x80x9cdistylium racemosumxe2x80x9d and xe2x80x9cbetula schmidtii regelxe2x80x9d. Although Isunoki does not have any English name, Onoore is usually translated in English as xe2x80x9cbirchxe2x80x9d or xe2x80x9cOnoore birchxe2x80x9d. The damper felts 8 are fixed to the lower surface of the damper head 7A, and are spaced from one another in the fore-and-aft direction.
While the key 2 is resting in the rest position, the rear portion of the key 2 is spaced from the damper lever 2, and the damper head assembly 7 urges the damper wire 6 downwardly due to the self-weight. The damper wire 6 in turn urges the damper lever 2 in the clockwise direction around the damper lever flange 9. However, the pair of damper felts 8 is held in contact with the set of strings 3, and keeps the damper lever 4 spaced from the rear portion of the key 2.
When the pianist depresses the front portion of the key 2, the front portion of the key 2 sinks toward the front rail, and, accordingly, the rear portion of the key 2 is lifted upwardly. The rear portion of the key 2 is brought into contact with the damper lever 4, and gives rise to rotation of the damper lever 4 around the damper flange 9 in the counter clockwise direction. Although the damper block 5 and the damper wire 6 are rotated around the damper flange 9 together with the damper lever 4, the guide rail 10 does not allow the damper wire 6 and, accordingly, the damper block 5 to be rotated around the damper flange 9. The guide rail 10 and the pin between the damper lever 4 and the damper block 5 convert the rotation of the damper wire 6 and the damper block 5 to straight motion. As a result, the damper block 5 and, accordingly, the damper wire 6 are moved upwardly as indicated by arrow A1. The damper wire 6 pushes up the damper head assembly 7, and, accordingly, the pair of damper felts 8 is spaced from the set of strings 3. Thus, the prior art damper 1 enters the tone generating position, and allows the set of strings 3 to vibrate for generating the piano tone. The depressed key 2 further actuates the action mechanism 2a, and causes the jack to escape from the hammer assembly 3a. The escape gives rise to the free rotation of the hammer assembly 3a, and the set of strings 3 is struck by the hammer assembly 3a. Thus, the prior art damper 1 at the tone generating position permits the set of strings 3 to vibrate for generating the piano tone.
A pedal mechanism 11 is provided for the prior art damper 1. The pedal mechanism 11 includes a foot pedal 12, a lifting rod 13 and a lifting rail 14. The foot pedal 12 is rotatably supported by a lyre box (not shown), and the lifting rod 13 is connected to the rear portion of the foot pedal 12. The lifting rod 13 upwardly extends, and projects into the piano case. The lifting rail 14 is swingably supported by the damper lever flange 9, and is located under the damper lever 4. Though not shown in FIG. 1, the pedal mechanism 11 is shared with the prior art dampers associated with other keys (not shown), and the lifting rail 14 laterally extends over all the damper levers or selected ones of the damper levers.
When the pianist wishes to prolong the piano tone or tones, he or she steps on the pedal 12. The pedal 12 is sunk, and, accordingly, the lifting rod 13 is moved upwardly. The lifting rod 13 pushes the lifting lever 14, and is rotated around the damper lever flange 9 in the counter clockwise direction. Accordingly, the lifting rail 14 is brought into contact with the lower surfaces of the damper levers 4, and the damper levers 4 are rotated around the damper lever flange 9 in the counter clockwise direction. This results in that the damper head assemblies 7 are spaced from the set of strings 3. Thus, the pedal mechanism 11 can keep the damper head assemblies 7 spaced from the associated sets of strings 3 regardless of the key positions. For this reason, even though the pianist releases the key 2, the pedal mechanism 11 supports the self-weight of the damper head assembly 7, and keeps the set of strings 3 vibrating.
As described hereinbefore, the notes of scale are assigned to the keys 2, and the associated sets of strings 3 generate the piano tones at the given notes. The piano tones are generally broken down into a lower pitched part, a middle pitched part and a higher pitched part, and the strings 3 are different in the diameter, length and number from one another. A single or two strings 3 are assigned each note of the lower pitched part, two or three strings 3 are assigned each note of the middle pitched part, and three strings are assigned each note of the high pitched part. The strings assigned a lower pitched tone are thicker and longer than the strings assigned a higher pitched tone, and widely vibrate rather than the strings assigned the higher pitched tone. This means that the vibrating energy is different depending upon the strings 3. Accordingly, the damper head assemblies 7 are designed equally to absorb the vibrations regardless of the size of the strings 3. In order to make the vibration absorbing capability equalized, the prior art dampers 1 are designed to be different in weight from one another. The weight of the prior art damper 1 is decreased from the lowest pitched tone toward the highest pitched tone. However, it is impossible to regulate the weight by only changing the size of the damper head 7A. Metal pieces 15 of lead are embedded into the damper lever 4 for regulating the weight appropriately. The total weight of the metal pieces 15 are decreased from the lowest pitched tone toward the highest pitched tone. Thus, it is necessary to change the metal pieces 15 as well as the damper head 7A for appropriately regulating the vibration absorbing capability of the prior art damper 1.
The following problems are encountered in the prior art damper 1. First, the weight of the damper head 7A is liable to be dispersed among the products. This is because of the fact that the specific weight of the hard wood is varied depending upon the age of the tree and the district where the tree was grown. Under these circumstances, even if the manufacturer strictly designs the prior art dampers 1 for the sets of strings assigned the different notes, the dispersion is unavoidable among the products.
Another problem is the increased production cost. The hard wood is getting drained. It is difficult to obtain those kinds of hard wood stably and economically. As a result, the production cost is increased. Another factor is low productivity of the damper levers 4. The manufacturer determines the dimensions of the holes, and forms the holes in each of the damper levers 4. The metal pieces are tailored, and are embedded into the damper levers 4. Thus, the damper levers 4 are regulated in weight through a series of steps, and the complicated steps are causative of the high production cost.
Yet another problem is the durability of the damper levers 4. As described hereinbefore, the damper levers 4 are formed of wood, and the metal pieces 15 are embedded in the damper levers 4. Even if the metal pieces 15 are snugly received in the holes formed in the damper levers 4, the damper levers 4 of wood become dry, and the holes are deformed. Gap takes place between the damper lever 4 and the metal pieces 15. The gap is an origin of noise, and the metal pieces 15 are liable to be dropped from the damper lever 4.
Still another problem is the environmental pollution. The metal pieces 15 are formed of lead, and are directly exposed to the environment. Although the lead is large in specific weight and easy for machining, the lead is undesirable from the aspect of the environment. When the damper levers 4 are worn-out, the metal pieces 15 of lead give rise to environmental pollution in so far as they are not carefully handled.
It is therefore an important object of the present invention to provide a damper, which is strictly regulable in weight, economical, durable and free from the environmental pollution.
It is another important object of the present invention to provide a keyboard musical instrument, which is equipped with the damper.
To accomplish the object, the present invention proposes to form at least one component of powder-containing synthetic resin.
In accordance with one aspect of the present invention, there is provided a damper for absorbing vibrations of a string comprising a damper lever actuated for rotation by a key, a damper assembly having a damper head and a vibration absorbing member fixed to the damper head, and changed between a rest position where the vibration absorbing member is held in contact with the string and a tone generating position where the vibration absorbing member is spaced from the string and a link mechanism connected between the damper lever and the damper head for transmitting a force from the damper lever to the damper assembly, wherein at least one of the damper lever and the damper head is formed of powder-containing synthetic resin.
In accordance with another aspect of the present invention, there is provided a keyboard musical instrument comprising at least one key rotated with respect to a stationary member when a force is exerted thereon, an action mechanism actuated by the at least one key when the force is exerted on the at least one key, a hammer linked with the action mechanism and driven for free rotation after the force is exerted on the at least one key, a string struck with the hammer at the end of the free rotation and a damper including a damper lever actuated by the at least one key, a damper head, a vibration absorbing member attached to the damper head and changed between a rest position where the vibration absorbing member is held in contact with the string and a tone generating position where the vibration absorbing member is spaced from the string, wherein at least one of the damper lever and the damper head is formed of powder-containing synthetic resin.